Children diagnosed with Kawasaki disease prior to the eighth day of fever will be randomized to receive traditional therapy, intravenous immunoglobulin (IVIG) 2 g/kg over 8-12 hours, or experimental therapy, intravenous methyprednisolone (IVMP), 30 mg/kg in D5W over 2 hours on each of two consecutive days. All children will otherwise receive treatment according to current standards of care. Any child receiving either IVIG or IVMP therapy who is febrile 48 hours after treatment will receive IVIG (salvage therapy), according to current treatment guidelines.